Wear part intended for a crusher and a method of manufacturing the same

ABSTRACT

A wear part ( 5 ) for detachable mounting on a supporting part in an impact-type multi-action crusher is at least partly manufactured by hot isostatic pressing. The wear part ( 5 ) has a body ( 19 ) for mounting of the wear part ( 5 ) on the supporting part and a crushing layer ( 20 ) which is attached to the body ( 19 ) and which is adapted to be brought, during operation of the crusher, into repeated contact with a raw material that is to be crushed. The body ( 19 ) is made of a substance which is easy to machine to narrow tolerances, and the crushing layer ( 20 ) is made of a material ( 27, 28 ) of high abrasive resistance. In a method of manufacturing the above wear part ( 5 ), the following steps are carried out: introducing at least one powder material ( 27, 28 ) into a capsule, degassing and sealing the capsule, subjecting the material ( 27, 28 ) in the capsule to hot isostatic pressing to form a crushing layer ( 20 ), and then after treatment of the wear part ( 5 ).

FIELD OF THE INVENTION

The present invention relates to a wear part for detachable mounting ona supporting part in an impact-type multi-action crusher. The inventionalso relates to a method of manufacturing such a wear part.

BACKGROUND OF THE ART

Impact-type multi-action crushers, such as gyratory crushers and jawcrushers, crush a raw material, such as a stone block, ore block,concrete or brick block or the like, by a wear part being repeatedlymoved towards the raw material to crush it against a counterbody. Thewear part is supported by a supporting part which transmits thenecessary force from a motor, moment arm, shaft or the like to the wearpart. The crushing operation causes wear on the wear part, whichtherefore now and then must be detached from the supporting part andreplaced.

For maximum life, the wear part is made of a material which has maximumabrasive resistance. The wear part is usually cast from what is referredto as Hadfield steels. These steels, which are described, for instance,in U.S. Pat. No. 5,069,871 and EP 0 692 548, are austenitic manganesesteels. A Hadfield steel has the property that the surface of the steelis hardened (deformation hardening) when the steel is acted upon by theraw material in the crusher, which results in good abrasive resistance.

For the supporting part to give sufficient support to the wear part,which is necessary to prevent the wear part from being deformed orcracking or from deforming the supporting part, the abutment surface ofthe wear part on the supporting surface of the supporting part must bemachined to narrow tolerances. The problem is that the Hadfield steelsalso in such machining will be deformation-hardened, which makesmachining difficult and time consuming.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a wear part for animpact-type multi-action crusher, said wear part having good abrasiveresistance and being easy to machine to narrow tolerances.

This object is achieved by a wear part for detachable mounting on asupporting part in an impact-type multi-action crusher, said wear partbeing characterized in that the wear part is at least partlymanufactured by hot isostatic pressing, and that the wear part has abody for mounting of the wear part on the supporting part and a crushinglayer which is attached to the body and adapted to be brought, duringoperation of the crusher, into repeated contact with a raw materialwhich is to be crushed, the body being made of a substance which is easyto machine to narrow tolerances, and the crushing layer being made of amaterial of high abrasive resistance. By the wear part being dividedinto a body and a crushing layer, each part can be given the propertiesthat are the most important ones for the part in question. Thus, thecrushing layer is optimized for good abrasive resistance and the bodyfor good machinability. By hot isostatic pressing, parts withcomplicated geometric structures can be produced also of materials thatcould otherwise not be used.

According to a preferred embodiment, the crushing layer is made of atleast one powder material which has been subjected to hot isostaticpressing, the substance of which the body is made also having goodweldability. There are a plurality of powder materials which aresuitable as crushing layer and which can be subjected to hot isostaticpressing to form such a layer. A body which has good weldability isadvantageous since the wear part is often fixed by welding.

Preferably, the crushing layer comprises at least two powder materials,which, without first being completely mixed with each other, have beensubjected to hot isostatic pressing and which, after said pressing andsubsequent aftertreatment, have different abrasive resistances, thecrushing layer having portions of different abrasive resistances. Theuse of at least two materials makes it possible to vary the abrasiveresistance of the crushing layer to obtain specific properties, such asimproved abrasive resistance in some portions and lower abrasiveresistance in other portions. Since the two materials are not mixed witheach other, or at least not completely mixed with each other, therewill, after the hot isostatic pressing, be portions with differentabrasive resistances. If a highly abrasive resistant material, which isexpensive, is used, this can be located in the portions of the crushinglayer where the highest abrasive resistance is required, while a lessexpensive material can be used in the remaining portions. The materialwhich after pressing and after-treatment has the highest abrasiveresistance is therefore conveniently arranged in the portions of thecrushing layer where the greatest wear is to be expected. In this way, amore even wear is obtained over the surface of the wear part, whichensures a longer life of the wear part.

Preferably, the crushing layer and the body are joined by a bondingzone. The bonding zone, which may be formed, for instance, when a powdermaterial in contact with a compact material is subjected to hotisostatic pressing, results in a safe connection between the body andcrushing layer over the entire contact surface and renders it possibleto do without a screw joint, weld joint and the like.

The body is suitably at least partly made of a substance selected from agroup consisting of carbon steels and low alloy steels. These substancesare easy to machine, have good weldability and are available at a lowprice. A body made of one of these substances can, for instance, becast, machined or forged to the desired basic shape and then be finishedto narrow tolerances. The body can also be made of a powder of one ofthe above substances, which is then subjected to hot isostatic pressing.

Preferably, a first portion of the crushing layer is made of at leastone first powder material and, located downstream of said first portionin the direction of flow of the raw material, a second portion of thecrushing layer is made of at least one second powder material, which,after subjecting the materials to hot isostatic pressing and subsequentaftertreatment, has higher abrasive resistance than the first material,whereby the second portion has higher abrasive resistance than the firstportion. Wear is usually greatest in the portions located downstream inthe direction of flow of the raw material since a larger number ofobjects are to be crushed in these portions. By locating the materialhaving the highest abrasive resistance in these portions, it is thuspossible to extend the life of the wear part. According to a still morepreferred embodiment, the first material gradually merges into thesecond material in such a manner that the crushing layer obtains anabrasive resistance which increases gradually in the direction of flowof the raw material and which corresponds to the wear load in operationso that the profile of the wearing layer is kept essentially intactduring the life of the wear part. This has the advantage that thecrusher will have essentially the same and, thus, predictable capacityduring the entire life of the wear part.

According to a preferred embodiment, the crushing layer has at least oneprotrusion protruding from the crushing layer and being made of at leastone powder material which, after subjecting the powder materials to hotisostatic pressing and subsequent aftertreatment, has higher abrasiveresistance than the powder material or materials of which the parts ofthe crushing layer which surround the protrusion are made. Theprotrusion will be exposed to particularly great wear load. At the sametime the protrusion is, in the cases when it is being used, critical tothe function of the wear part. By locating the most wear resistantmaterial in the protrusion, the life of the wear part can thus beextended significantly.

According to another preferred embodiment, the crushing layer has atleast one protrusion protruding from the crushing layer and being madeby casting, sintering or forging and having higher abrasive resistancethan the powder material or materials of which the parts of the crushinglayer which surround the protrusion are made. Thus the protrusion can bemade of materials, such as sintered tungsten carbide, which haveexcellent abrasion resistance but are better suited for othermanufacturing methods than hot isostatic pressing. The protrusion canalso be made of cast materials, such as Hadfield steels. Then it ispossible to deformation-harden the protrusion in advance, beforeattaching it to the crushing layer. The parts of the crushing layerwhich surround and fix the protrusion are also in these cases made of atleast one powder material which has been subjected to hot isostaticpressing.

The wear part can be an inner shell or an outer shell for use in agyratory crusher. In gyratory crushers, the requirements for narrowtolerances in the abutment of the wear part on the supporting surfaceare strict, which makes the invention particularly suitable for thistype of crushers.

According to a particularly preferred embodiment, the protrusion has theform of a rotationally symmetric step extending round the crushinglayer. The step improves the crushing of the raw material and improvesthe grain shape of the crushed raw material. According to a preferredembodiment, the crushing layer comprises at least two powder materials,which, after subjecting the materials to hot isostatic pressing, havedifferent hardnesses, the softer of the two materials being located in afirst layer closest to the body and the harder of the two materialsbeing located in a second layer on the outside of the first layer. As aresult, a very hard, but brittle, material can be used in the outerlayer of the crushing layer and be supported by a softer material placedunder the outer layer.

The object of the present invention is also to provide a method ofmanufacturing a wear part for an impact-type multi-action crusher, saidwear part having great abrasive resistance and being easy to machine tonarrow tolerances.

According to the invention, this object is achieved by a method ofmanufacturing a wear part for detachable mounting on a supporting partin an impact-type multi-action crusher, said method being characterizedin that the wear part is manufactured as a body for mounting of the wearpart on the supporting part and a crushing layer which is attached tothe body and adapted to be brought, during operation of the crusher,into repeated contact with a raw material which is to be crushed, thebody being made of a substance which is easy to machine to narrowtolerances, and the crushing layer being made of a material of highabrasive resistance by at least one powder material being introducedinto a capsule, the capsule being degassed and sealed and the materialin the capsule being subjected to hot isostatic pressing, after whichthe wear part is subjected to aftertreatment. By the wear part beingdivided into a body and a crushing layer, each part can be given theproperties that are the most important ones for the part in question.Thus, the crushing layer is optimized for good abrasive resistance andthe body for good machinability. By hot isostatic pressing, parts withcomplicated geometric structures can be manufactured. The abrasiveresistant materials that are normally of interest for use in thecrushing layer are often very difficult to machine to complicatedgeometric structures.

According to a preferred method, at least two powder materials, whichafter hot isostatic pressing and subsequent aftertreatment havedifferent abrasive resistances, are introduced into the capsule withoutbeing completely mixed with each other, in such a manner that thematerial of the highest abrasive resistance is arranged in the parts ofthe capsule which correspond to the portions of the crushing layer wherethe greatest wear is to be expected. If a highly abrasive resistantmaterial, which is expensive, is used, this can be located in theportions of the crushing layer where the highest abrasive resistance isrequired, while a less expensive material can be used in the remainingportions. A further advantage is that the wear on the wear part will bemore even than if the same material is used in the entire crushinglayer. Unevenly worn crushing layers constitute a common source offunctional troubles and shortened life of wear parts.

Preferably, the body of the wear part is used as a wall in the capsuleto be joined with the crushing layer. This saves a wall in the capsulethat is used. Moreover, the advantage is achieved that the body andcrushing layer are joined by a bonding zone which will be very strongsince it covers the entire surface where the body and the crushing layerare in contact with each other. Nor is a weld joint, bolt joint or thelike required to hold the body and the crushing layer together.

According to a preferred method, at least one first powder material isintroduced into a first part of the capsule which corresponds to a firstportion of the crushing layer and at least one second powder material isintroduced into a second part of the capsule which corresponds to asecond portion of the crushing layer, which second portion is locateddownstream of the first portion in the direction of flow of the rawmaterial, the second material in the second portion, after subjectingthe materials to hot isostatic pressing and subsequent after-treatment,having higher abrasive resistance than the first material. Uneven wearis a great problem in many crushers, especially in gyratory crushers.Owing to the wear which usually is greatest in the portions positioneddownstream in the direction of flow of the raw material, the crushercapacity of crushing a raw material is reduced and, after a certainperiod of operation of the wear part, the crusher cannot crush the rawmaterial to the same small sizes, and therefore the wear part must bereplaced. By a more abrasive resistant material being used in theportion of the crushing layer which is close to the end point of theflow of raw material, the life of the wear part can be increasedsignificantly. According to a particularly preferred-method, the firstmaterial and the second material are introduced into the capsule in sucha manner that the first material gradually merges into the secondmaterial, the crushing layer obtaining an abrasive resistance thatincreases gradually in the direction of flow of the raw material andcorresponds to the wear load in operation, so that the profile of thecrushing layer is kept essentially intact during the life of the wearpart. As mentioned above, this has the advantage that the performance ofthe crusher will be constant and thus predictable for the entire life ofthe crusher.

According to a preferred method, the crushing layer is manufactured withat least one protrusion protruding from the crushing layer, at least onepowder material being introduced into the capsule in the parts of thecapsule which correspond to the protrusion and at least one other powdermaterial being introduced into the parts of the capsule which correspondto the parts of the crushing layer which surround the protrusion, thematerial of the protrusion, after subjecting the materials to hotisostatic pressing and subsequent after-treatment, having higherabrasive resistance than the material of the parts of the crushing layerwhich surround the protrusion. As mentioned above, the life of theprotrusion will thus be increased, which ensures the above advantages oflonger life for the entire wear part.

According to another preferred method, the protrusion is manufactured ina first step by hot isostatic pressing, after which the parts of thecrushing layer which surround the protrusion are manufactured in asecond step. This method results in improved control of the conditionsunder which the protrusion is manufactured. The extent and connectionsurfaces of the protrusion to the surrounding material can also beformed with greater accuracy. It is also possible to make the protrusionof a material that requires hot isostatic pressing in conditions, asregards, for instance, temperature and pressure, that are unsuitable forthe surrounding material.

According to another preferred method, the crushing layer has at leastone protrusion protruding from the crushing layer and being made in afirst step by sintering, casting or forging, the protrusion in a secondstep being arranged in the capsule and at least one powder materialbeing introduced into the parts of the capsule which correspond to theparts of the crushing layer which surround the protrusion, theprotrusion, after subjecting the materials to hot isostatic pressing andsubsequent aftertreatment, having higher abrasive resistance than theparts of the crushing layer which surround the protrusion. As mentionedabove, this makes it possible to select for the protrusion also suchabrasive resistant materials as are not best suited for hot isostaticpressing.

According to a preferred method, the protrusion is formed as a step. Thestep ensures, as mentioned above, advantages in crushing. Preferably,the body is at least partly made of a substance selected from a groupconsisting of carbon steels and low alloy steels. Owing to thesesubstances, the abutment surface of the body is easy to machine tonarrow tolerances, as mentioned above.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in more detail by way of embodimentsand with reference to the accompanying drawings.

FIG. 1 shows a gyratory crusher.

FIG. 2 is a cross-sectional view of a portion of the crusher in FIG. 1and shows an inner shell and an outer shell according to prior art.

FIG. 3 is a cross-sectional view and shows a wear part according to theinvention in a first embodiment, formed as an inner shell.

FIG. 4 is a cross-sectional view and shows a wear part according to theinvention in a second embodiment, formed as an inner shell.

FIG. 5 is a cross-sectional view and shows a wear part of the inventionin a third embodiment, formed as an inner shell.

FIG. 6 is a cross-sectional view and shows a wear part according to theinvention in a fourth embodiment, formed as an inner shell.

FIG. 7 is a cross-sectional view and shows wear parts according to theinvention formed as an inner shell and an outer shell, intended for acrusher that is normally used in coarse crushing.

FIG. 8 is a cross-sectional view and shows a capsule for manufacturingwear parts according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a gyratory crusher 1. The crusher 1 has a crusher shaft 2which at its lower end 3 is eccentrically mounted. In its upper portion,the crusher shaft 2 has a crushing head 4. The crushing head 4 has aninner shell 5, which in the simultaneous rotary and oscillating motionsof the crusher shaft 2 crushes raw materials, that are supplied to theupper portion 6 of the crusher 1, against an outer shell 7. A crushingchamber 8 is formed between the inner shell 5 and the outer shell 7. Asa rule, the function of the crusher 1 is determined by the gap S whichis the smallest distance between the inner shell 5 and the outer shell 7of the crusher 1. The crusher shaft 2 can by means of an adjustingdevice 9 be moved in the vertical direction. Thus, the gap S of thecrushing chamber 8 can be adjusted, thus allowing setting in a desirablemanner the relation between the amount of material that is crushed bythe crusher 1 and the size of the crushed material.

FIG. 2 shows an inner shell 5′ and an outer shell 7′ of prior-art type.As illustrated, the inner shell 5′ is supported by a supporting part inthe form of a support cone 10 included in the crushing head 4 and theouter shell 7′ on a supporting part 11 in the form of an intermediatering. The inner shell 5′ is held on the support cone 10 by a nut 12,which by means of a ring 13, that is welded to the inner shell 5′ andthe nut 12, holds the inner shell 5′ on the support cone 10. The outershell 7′ is attached to a base 11′ by means of a bolt joint. Whenoperating the crusher, raw materials are supplied to the inlet 14 of thecrusher and conveyed in the direction of flow P of the raw material, (inFIG. 2 indicated by an arrow) downwards through the crusher 1. Accordingto prior-art technique, both the inner shell 5′ and the outer shell 7′are made of cast manganese steel. The abutment surface 15 of the innershell 5′ on the support cone 10 is machined to narrow tolerances incomplicated turning operations. In the same way, the abutment surfaces16 of the outer shell 7′ on the supporting part 11 are machined tonarrow tolerances. To ensure a correct gap 5, usually also the crushingsurface 17 of the inner shell 5′ and the crushing surface 18 of theouter shell 7′ are machined by means of complicated turning operations.

The dashed lines in FIG. 2 indicate the extent of the inner shell 5′ andthe outer shell 7′ after a period of wear. The wear makes it necessaryto move the crusher shaft 2 upwards to maintain a constant gap S. Whenthe crusher shaft 2 has reached its uppermost position, the inner shell5′ must be replaced without its upper portion being worn out.

FIG. 3 shows a first embodiment of a wear part according to theinvention in the form of an inner shell 5 a for the gyratory crusher 1.The inner shell 5 a has a body 19 made of a carbon steel which is easyto machine. The abutment surface 15 of the body 19 for abutment on thesupport cone 10 has been turned to narrow tolerances for a good fit tothe support cone 10. The inner shell 5 a has a crushing layer 20. Thecrushing layer 20 is made of two different powder materials 21 and 22,for instance Elmax and Vanadis 10 made by Uddeholm AB, SE, which havebeen subjected to hot isostatic pressing.

In hot isostatic pressing the body 19 and the crushing layer 20 will bepartly joined by diffusion and form a bonding zone 20′ which extendsalong the entire contact surface between the body 19 and the crushinglayer 20.

In the embodiment shown in FIG. 3, two powder materials 21, 22 are usedin the crushing layer 20 as mentioned above. The first material 21 isplaced at the end, located at the inlet 14, of the inner shell 5 a in afirst portion 21′ of the crushing layer 20, and the second material 22is placed in a second portion 22′ of the crushing layer 20, which ispositioned downstream of the first portion 21′ in the direction of flowP of the raw material. The materials 21, 22 are selected so that thesecond material 22 has higher abrasive resistance than the firstmaterial 21 after both materials being subjected to hot isostaticpressing. In a portion 23 of the crushing layer 20, the first material21 gradually merges into the second material 22 in the direction of flowP of the raw material. In the embodiment in FIG. 3, uneven wear thatarises in prior-art technique (FIG. 2) is thus avoided owing to the factthat the abrasive resistance of the crushing layer 20 along thedirection of flow P of the raw material has been adjusted to the actualwear. As is evident from FIG. 3, the crushing layer 20 has on itsoutside a special curvature. This curvature, which is described, forinstance, in GB2,123,314, is intended to maintain a constant inlet 14 asthe crusher shaft 2 moves upwards subsequent to wear. Thus the innershell 5 a will have an almost constant profile during its entire life,which ensures that the correct gap S can be set without the capacity ofthe crusher 1 decreasing.

FIG. 4 shows a second embodiment of a wear part according to theinvention in the form of an inner shell 5 b. Like in the embodimentshown in FIG. 3, this inner shell 5 b has a body 19 having an abutmentsurface 15 and being made in the manner as described above, and acrushing layer 20. The crushing layer 20 has, in its portion positionedat the inlet 14, a number of shoulders or steps 24, 25. The steps 24,25, which can be analogized to rotationally symmetric stairs extendinground the crushing layer 20 and which are positioned upstream of aportion 26, improve the possibility of crushing the raw material tosmaller pieces and also improve the grain shape of the crushed rawmaterial. The steps 24, 25, which in operation are exposed to heavywear, are made of a powder material 27 having a higher abrasiveresistance than the material 28 of which the remainder of the crushinglayer 20 is made, after the materials being exposed to hot isostaticpressing. The steps 24, 25 will thus last longer than in the case ifthey had also been made of the material 28, thereby increasing theoperating time in which the shell S exhibits the desired function.

The steps 24, 25 can be made at the same time as the remainder of thecrushing layer 20 in the above isostatic pressing. However, it is alsopossible to make the steps 24, 25 in a first step, i.e. a firstprocessing step, by hot isostatic pressing and then in a second step,i.e. a second processing step, make the remainder of the crushing layer.It is also possible to make the steps 24, 25 by casting, sintering, forinstance of tungsten carbide, or forging, after which the parts of thecrushing layer 20 which surround the steps 24, 25 are made of a powdermaterial that is subjected to hot isostatic pressing.

FIG. 5 illustrates a third embodiment of a wear part according to theinvention in the form of an inner shell 5 c. This embodiment differsfrom the embodiment shown in FIG. 4 essentially only by its inner shell5 having larger shoulders or steps 29. The steps 29, which may beanalogized to rotationally symmetric stairs extending round the crushinglayer 20, give the advantage that a smaller crushing surface 30 isobtained, thus allowing the raw material to be crushed with greaterforce against this surface 30. The steps 29 thus prevent large objectsfrom reaching the crushing surface 30. A certain degree of wear by theraw material also takes place in the area of the steps 29.

FIG. 6 illustrates a fourth embodiment of a wear part according to theinvention in the form of an inner shell 5 d. In this embodiment, thecrushing layer 20 has at least two different layers 31, 32, viz, a lowerlayer 31 closest to the body 19 and an upper layer 32 which is harderthan the lower layer 31. The hard, but brittle, layer 32 is supported bythe softer lower layer 31. The outer surface of the harder layer 32 thusconstitutes the crushing surface 17 of the crushing layer 20.

Both the softer layer 31 and the harder layer 32 are made by hotisostatic pressing of powder materials. The layers 31, 32 can be madesimultaneously. Alternatively, the softer layer 31 can be made in afirst step and the harder layer 32 can be made in a subsequent secondstep. It is also possible to make the lower layer 31 of a cast manganesesteel, for instance a Hadfield steel. The manganese steel has relativelyhigh abrasive resistance, which is advantageous if the upper layer 32should be damaged at any point.

FIG. 7 illustrates a primary gyratory crusher 33. The primary gyratorycrusher 33 is a type of gyratory crusher which is used for crushinglarge objects. Thus, the inlet 14 is very wide. The outer shell 34 ofthe primary gyratory crusher 33 is divided into a number of segments 35,36 which are attached to a supporting part 11. The segment 35 has acrushing layer 37 which is made of a powder material that has beensubjected to hot isostatic pressing and that is attached to a body 38.The body 38 is made of a carbon steel. The segment 36 positioneddownstream of the segment 35 in the direction of flow P of the rawmaterial has a crushing layer 39 which is made by hot isostatic pressingand is attached to a body 38. The crushing layer 39 has higher abrasiveresistance than the crushing layer 37. Since the wear is smaller in theportions of the crusher 33 which are positioned close to the inlet 14,the segments 35, 36 will be worn at approximately the same rate inoperation of the crusher, which ensures an even profile of the outershell 34. The crusher 33 also has an inner shell 5 e which isreplaceably attached to a support cone 10. This shell 5 e can be formedin the manner as described above with reference to FIGS. 3-6.

The hot isostatic pressing, which is described, for instance, in U.S.Pat. No. 3,695,597, is carried out by means of a capsule 40 (see FIG.8). In the capsule 40, the body 19 is used as a wall. Otherwise, thecapsule 40 has the geometric shape that is desired for the completedinner shell 5 e. Steps 29, if any, that have been made in advance by,for instance, hot isostatic pressing, sintering, casting or forging, areplaced in the capsule 40 in the positions as required in the completedcrushing layer 20. In the capsule 40, at least one powder material isintroduced in at least one opening 41. After vibrating, degassing andsealing, the capsule 40 is exposed to heat and pressure, whereby thepowder material is deformed and joined by diffusion. The capsule 40 canthen be removed. In some cases, the capsule 40 is joined with thecrushing layer 20 and becomes part thereof. After subsequent treatment,comprising, for instance, tempering, the inner shell 5 e is ready foruse. Owing to the conditions in pressing, the crushing surface 17 of theshell 5 e need not be machined at all but satisfies the tolerances thatare required for the selected gap S. The abutment surface 15 of the body19 can be machined either before pressing or after the same.

It will appreciated that a number of modifications of the embodimentsdescribed above are feasible within the scope of the invention.

Thus, for instance an inner shell 5 or an outer shell 7 can be formed,in which the steps 24, 25, 29 shown in FIGS. 4 and 5 are combined with acrushing layer 20 containing the combinations of powder materials 21,22, 31, 32 shown in FIG. 3 and/or FIG. 6, said materials being subjectedto hot isostatic pressing with a view to forming different portions andlayers. Of course, a plurality of, for instance 2-7, different powdermaterials can be used for the different layers, portions and steps ofthe wear part. The materials can either merge more or less graduallyinto each other or be separated by distinct limits. Such limits mayconsist of, for instance, thin metal foils that are inserted into thecapsule 40.

Wear parts according to the invention can be manufactured, inter alia,for the above-described gyratory crushers and jaw crushers. Jaw crushersin general are described, for instance, in WO 00/25926 and U.S. Pat. No.4,927,089. A jaw crusher has two jaws each having the shape of arelatively flat surface, one jaw crushing the raw material against theother jaw by a reciprocating motion. A raw material is introduced intothe upper portion of the jaw crusher and passed downwards through thecrusher in an essentially vertically downward direction of flow of theraw material. When passing downwards through the jaw crusher, the rawmaterial will be crushed a plurality of times to increasingly smallerdimensions. The jaws comprise supporting parts to which wear partsaccording to the invention can be attached by welding or bolting. Agreat deal of the wear will arise in the lower parts of the jaw crusherwhere a very large number of objects of the raw material are to becrushed. In many cases it will thus be convenient to use wear parts inthe jaw crusher that have been manufactured, for instance, according tothe principles as described in connection with FIGS. 3 and 7. Gyratorycrushers and jaw crushers are impact-type multi-action crushers, i.e.crushers in which a piece of the raw material is crushed several timeswhile passing through the crusher and by impact between two surfacesthat are accelerated towards each other and strike against the rawmaterial.

The body 19 is made of a substance which is easy to machine but which atthe same time has the mechanical strength that is necessary to supportthe crushing layer 20. The body can be cast, forged or cold- and/orhot-worked to the correct shape. Since the body is not in contact withthe raw material, it can be made of a substance of low abrasiveresistance. Low abrasive resistance often makes the substance easy tomachine. The substances that are most convenient for the body are carbonsteels and low alloy steels. The abutment surface 15, 16 of the body onthe supporting part 10, 11 can be machined to narrow tolerances, forinstance by turning, milling or grinding.

Substances that are easy to weld are particularly advantageous assubstance for the body. The wear part can be attached to the supportingpart by means of a weld that should resist high loads. Particularlysuitable substances are therefore carbon steels and lower alloy steels.

The segments 35, 36 illustrated in FIG. 7 can also each be formedaccording to the principles described above in connection with FIGS.3-6. Thus, wear parts for gyratory crushers as well as jaw crushers canbe made in several segments. Each segment may either comprise a singlepowder material or a plurality of materials. The segments may alsocomprise steps.

When a plurality of steps 24, 25, 29 are used, they can be made of thesame material, but also of different materials and by different methods.For instance, it is possible to make the steps 24 of a powder materialthat is subjected to hot isostatic pressing, and the step 25 of a stillharder material which has been made in advance by sintering.

It is also possible to manufacture a body and a crushing layer eachseparately, for instance by casting, machining, forging or hot isostaticpressing, and then attach the body and the crushing layer to each otherby hot isostatic pressing, also referred to as diffusion bonding.

1-23. (canceled)
 24. A wear part configured for detachable mounting on asupporting part in an impact-type multi-action crusher, the wear partbeing at least partly manufactured by hot isostatic pressing, andincluding a body for mounting of the wear part on a supporting part, anda crushing layer attached to the body and adapted to be brought intorepeated contact with a raw material which is to be crushed; the bodycomprising a substance easily machinable to narrow tolerances than thecrushing layer; and the crushing layer comprising a material of higherabrasive resistance than the body.
 25. A wear part as claimed in claim24, wherein the crushing layer comprises at least one powder materialsubjected to hot isostatic pressing; and the substance of which the bodyis comprised has good weldability properties.
 26. A wear part as claimedin claim 24 wherein the crushing layer comprises at least two powdermaterials subjected to hot isostatic pressing without first beingcompletely mixed with each other, said powder materials, following thepressing and subsequent after-treatment, having different respectiveabrasive resistances.
 27. A wear part as claimed in claim 26, whereinthe powder material having a highest abrasive resistance is arranged ata highest-wear region of the crushing layer.
 28. A wear part as claimedin claim 24 wherein the crushing layer and the body are joined togetherat a bonding zone.
 29. A wear part as claimed in claim 24 wherein thebody at least partly comprises one of carbon steels or low alloy steels.30. A wear part as claimed in claim 24, wherein a first portion of thecrushing layer comprises at least one first powder material; a secondportion of the crushing layer located downstream of said first portionin a direction of flow of raw material to be crushed comprising at leastone second powder material; the second powder material, following hotisostatic pressing and subsequent after-treatment of the first andsecond powder materials, having higher abrasive resistance than thefirst material.
 31. A wear part as claimed in claim 30, wherein thefirst material gradually merges into the second material in such amanner such that abrasive resistance of the crushing layer increasesgradually in a direction of raw material flow, the abrasive resistanceproperties arranged in corresponding relationship to the wear load inoperation, wherein the crushing layer is kept essentially intact duringwearing of the wear part.
 32. A wear part as claimed in claim 24,wherein the crushing layer comprises first and second powder materials,and at least one protrusion formed of the second powder material; thesecond powder material, following hot isostatic pressing and subsequentafter-treatment of the first and second powder materials, having higherabrasive resistance than the first powder material.
 33. A wear part asclaimed in claim 26, wherein the crushing layer has at least oneprotrusion formed by one of casting, sintering or forging, theprotrusion having higher abrasive resistance than a material of thecrushing layer disposed adjacent the protrusion.
 34. A wear part asclaimed in claim 33, wherein the protrusion is configured as arotationally symmetric step structure.
 35. A wear part as claimed inclaim 24 comprising a shell configured for use in a gyratory crusher.36. A wear part as claimed in claim 24, wherein the crushing layercomprises at least two powder materials, which, after the materialsbeing subjected to hot isostatic pressing, have different respectivehardnesses; a softest of the powder materials being located in a firstlayer closest to the body, and a hardest of the powder materials beinglocated in a second layer disposed outside of the first layer.
 37. Amethod of manufacturing a wear part configured for detachable mountingon a supporting part of an impact-type multi-action crusher, comprisingthe steps of: A) introducing at least one abrasive-resistant powdermaterial into a capsule, B) degassing and sealing the capsule, C)subjecting the degassed and sealed capsule to hot isostatic pressing toform a crushing layer, and D) causing the crushing layer to be attachedto a body formed of a substance which is less abrasive resistant andmore easily machinable to narrow tolerances than the crushing layer. 38.The method according to claim 37, wherein step A comprises introducing,without being mixed together, first and second powder materials, thesecond material having higher abrasive resistance than the firstmaterial following step C; wherein step A further comprises arrangingthe second powder material at a position of greatest wearing of thecrushing surface.
 39. The method according to claim 37, wherein step Dcomprises positioning the body to form a wall of the capsule during stepA.
 40. The method according to claim 37, wherein step A comprisesintroducing first and second powder materials into first and secondparts, respectively, of the capsule, wherein the second material islocated downstream of the first material in a rock flow direction, thesecond material exhibiting a higher abrasive resistance than the firstmaterial following step C.
 41. The method according to claim 40, whereinthe first material merges into the second material during step C, andthe crushing layer exhibits an abrasive resistance that progressivelyincreases from the first material to the second material.
 42. The methodaccording to claim 37 wherein step A includes arranging a first powdermaterial with a protrusion in the capsule, and arranging a second powdermaterial in the capsule adjacent the first material; wherein followingstep C, the first material has a higher abrasive resistance than thesecond material.
 43. The method according to claim 37, wherein step Aincludes arranging a first powder material with a protrusion in thecapsule, and subsequent to step C, affixing to the first material asecond material of less abrasive resistance than the first material. 44.A method of manufacturing a wear part configured for detachable mountingon a supporting surface of an impact-type multi-action crusher,comprising the steps of: A) forming a first crushing layer portion inthe form of a protrusion by one of sintering, casting, or forging, B)inserting the protrusion into a capsule, C) introducing into the capsuleat least one powder material adjacent to the protrusion, D) degassingand sealing the capsule, E) subjecting the degassed and sealed capsuleto hot isostatic pressing, whereafter the projection exhibits higherabrasive resistance than the adjacent material.
 45. The method accordingto claim 44, wherein the protrusion comprises at least one step-shapedstructure.
 46. The method according to claim 37, wherein the bodycomprises one of carbon steel or low alloy steel.